Functional genomics using CRISPR (Clustered Regulatory Interspaced Short Palindromic Repeats)/Cas (CRISPR-associated endonuclease)-based approaches has revolutionized biomedical sciences. Gene editing is also widespread in parasitology generally and its use is increasing in studies on helminths including flatworm and roundworm parasites. Here, we survey the progress, specifically with experimental CRISPR-facilitated functional genomics to investigate helminth biology and pathogenesis, and also with the burgeoning use of CRISPR-based methods to assist in diagnosis of helminth infections. We also provide an historical timeline of the introduction and uses of CRISPR in helminth species to date.